Pressure-tool for dental-castings.



H. SGHWEITZER. PRESSURE TOOL FOR DENTAL CASTING APPLICATION FILED JAN.17. 1912.

Patented Dec. 3, 1912.

2 SHEETS-SHEET 1.

INVENTOR I fimk: WW

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H. SGHWBITZER. PRESSURE TOOL FOR DENTAL GASTINGS.

APPLICATION FILED JAN.17, 1912.

r MM 7, in 0 A we M 1 0b S E t1 E d H m S w 2 HNESSES UNITED- STATES PATENT OFFICE.

EINRIGH'SCHWEITZER, or NEW YORKHN. Y.

PRESSURE-TOOL FOR- DENTAL CASTINGS.

Specification of Letters Patent Patented Dec. 3, 1912.

To all whom it maygcncan:

Be it known tliaty-IgHn'ixnu'ir St-{nu'srrzen, a subject of the German Emperor-Q residing'in the city. -c('-$!t'rn t}. .-and State of New lorlr hare invented ne r and useful l m- .p o \;em ents 1n Pressure -Tools? for; Dental Castings, of which the following is a specification. x

-I-n machines used'fur dent-uhqustings up to the, present the container liq-aiding the cru-- cible for the metal to be melted or cast. was tightened against the top-cover through' which the pressure. was transmitted by means of asbestos. "Even the latest type of-casting machines. such as the Taggar't inlay apparatus-Patent -9835.80Feb. 7. 1911,

- provides layers of asbestos foritightening the upper e-dgeofthe mold investment ring against the top, cover. Asbestos fittings often become defective through use, so that a loss of pres sure may occur at the moment of administration. ll relatiielv high pressure-was-therefore necessary in order to he xi'it l rout p 'csst'lre h'simuch as possible. before sure of forcing lthe molten metalinto the -mold.-*-The cruclblecontamer placedmto a flat receptacleiornpon the mold flask was liable to cool down from thesides when the "metalwas heated in the crhcible. Such a great-loss ofhea't was-often complained of. in the mold flask radiating from the open receptacleavhen the previouslv heatedjj mold and crucible container was plii 'ced under the pressure plunger, that the cast metal crystallized before it could be forced through *a-sm'all-sprue opening in all; parts of: the

mold.

Many methods of luaking dental castings were describedheretofore and arhile the. so called inlay casting process usually. provides to melt the metal over the mold and-to force it. atonce through a small. sprue opening into the mold cavity, I wish it to be understood that I do not consider anypartofthi method as my} invention and also that :the method of completing castings descrihef; hereafter in'connection with my tools is dependent from the processes that are piotectedby patents at thezpresent time.

Contrary to other mehods I prefer to have metal introduced into the mold cavity the pressure applied-i are-sam a we: the. inlet funnels illustrated on thc molds of my drawings explains that the molten metal will not be heldabove the mold cavity on account ofsurface extension or molecular P f r on .P of 5-1,

attraction, but is rather compelled to lm\ into the cavity on account of its grarirr. My invention i elatesjothe completion arid perfection ofcastings by m to :l-.-; and 6 I ipoint out as the main objects of my'im'entimrr-L- The insulation oflthe moldiin'a' receptacle or flask in which'the pressure is applied upon the cast metal.- '2. The arrztngemeut and position of the parts-of the-' 5 pressure flask on a support in combination with the-mold. T

Figure 1 'of the accompanying(ll-airing is avertical section; of the rece fiacle. mold, and base. F igQ'Zi-isa sectional ie\v of the'70 -receptacle turnedupside down. Fig. 3 represents the mold upon a heating frame. Fig. 4 shows in section the -1)ress\ire flask rcsting upon a base. and the'inold in the flask. vFig. 5 isa-sectional view of the-'receptacle, mold and base; 1F ig.. (i';sll(l.\tiS the receptacle and Fig. 7 then old turned u pside down, g.' ;8 "shows. the mold ins-i tion'in thepressure tlaslr f FigJQ exhibits} the mold in theplessure'flask' n' liiclris l es tr' g0 ing upon aniorablesu-pport th-e'secti ons of the flask areishou'n. openedi;- Fig.*-. 10- indi catesthe pressure flask closed; the up iier tion of the. flask being, movable." ig.'i 11. illustrates the flask withlthe ti'tosections "35 movable on brackets. f I I v The pressure flask; consists of 'aniupper section. N. and-a lowe1t-section, Whichare valve like ground and'fit-ted'to'nietieach other in the conical surfaces. K. The lower section is of'cup' shape and provided with .a bottom from which a taper t extei'idsto the insideor Outside-of the cup as illustrated in Fig.1.? and Fig. 6. This taper is prefer-= ably. made of conical-shape. '1 he; x'tqfiorf surface bf this taper. isffitte'd ib iito lthe '7 taper, T of the base 'Aconial ap th p 5 i LX -f. a it i E "i the" quick and accuratea djutnient the '==i we a the n e i earee he base ,'sfupport.- as the smaller-(end ofth'e proc- [Qes s 'cbne will easilv finditlie tleptl fif the r'c c'ess ionef. The bottomgo'fthe .cup'. @C may Qandti The mold preferably tvitluuit inetalfsur rounding is posted .inthe, center of th s infsitl atir-lgi oupenot;itouohinggtiie. grails of the pressure flask-thus allouiil1g,. fptj.,aeru mulaticn of heat andlpreventi'm l.ofra ljation. The investment of the mold ha Yin; a

funnel shaped inleton top is centered in the 3 and. 7) fitting,

onto the 'taper, .t, of the pressure'cup. T c'niold, rather prepared from dental inves ment plaster com pound only is a littlehigher than the cup;-

pressure cupby a. proccis or recess taper, t

thcruolditself is notscaled against a head part, cojver or disk, An aircushion, A, is foundbetween the walls of the mold and the inner wall of the cup, (hthis air cushion on-the lower end \vitlrtlie. interior of the .sections and closing of the flask before the insulates the mold, M, and heatapplied from two sides is rather accumulated in the mold.

The upper section of the flask, the cylind'erfh, does not touchthe top part of the mold when the flask is closed. The cylinder, N, centrally perforated and communicates flask and on the other cnd;\\'ith a sourcei ot air pressure generated either from a bulb 'or from the month or lungs of the operator.

Various means for supporting the'flaslc pressure is applied, may be used and although I do not limit myseltto one or the other Construction, I include-- the onesdescribed in the following as 'part ofmy in- .ventioh.

chamber, V,- and the freely remova'blecylin? der, N, is provided with-a rubber tube leading to a'source of air pressuifc; for example the one generated from the mouth, of a person by-a heavy expiration.

Fig. 8 represents a similar device pro-'- 7 viding a receding'conical-surface extension in the lower 'endof the mold fit-tihg upon a conical surface extension of the cup bottom that is projecting.ir 1t9 the interior space-of the cup,.C.- H J The sections of tl epressure .fiask be positioned one mo t'ab'l e :toward .theother as shown in the Fi s: nd{1( or'botli:maybe movable toward to remove the loivi flask-section' from the apparatus for thepurpose of-a'ttachi'ng the mold. i

In the construction shown in Fig; 9, the

lower section C, of the flask is movably posi- I tioncd on top of a metal cylinder, W, that is moved up and down in a bore hole, U, of a bracket, D. The up er secti0n,' N, is sta tionarily attached to t e bracket. X, and a double gas and oxygen blow pipe, E, is sup.- ported and adjusted to the vertical part, P, of the base F. The lever, L, raises the cylinder, YV, tightens the cub. C, against the up:

' er section of the 135161. which is in communication with a bulb,B; hand pressure is exerted uponthe rubber bulb, .B, as soon as the lever, L ls lowered-in its longer arm and therewith a seal of the flask seoiio is effected; by th-isactionf I generate p're' ure upon the molten metal whereby it isforced to completely fill the moldc'avity. A'movable positionis given to the upper flask section,"N, in the construction illustrated in Fig. 10. Avertiea'l bore hole in the bracket,

.Y, allows fqlflfl raising and lowering of 'theupper se'cticn'o'n top of which' a rubber bulb is directly attached. The cupfC, is

placed on 'the recess, TIE-which communi cates with-"the. i'acuum chamber, V, by La small. central perforation.

A double end gas andoxj'gen blow'p'ipe is adjusted in the slot, 7 of the vertical post, P The metal, I S, is heated. while theupper flask section is .held in an elevated position. .Assoon as the atmosphericpressure begins-to act upon the molten nietah'ip'ushing it downward, I' make the upper flask; section comedown by 'its own weight and immediately after the flask is closed iapply hand pressure 'on top of the rubber bulb, B. Fig. 11 of the drawing explains a con struction of a supporting base for the parts cf the pressure. flask, .whereby the upper.

section, X, with a compressible air container,

B, on top, and the; lower section, C arev mqvably; positioned on tlie-brackets,'-D and D. The cylinder, W, carrying on" top, the flask cup, C, can be forced upwardby means of the lever. L, orlspring, I, which is,set

advantage as the'lever controls the spring "and arrested bv the lock-bolt, J; thecomaction-as well as itmay increase the same I The bracket, D, arrests the upward motion" of the compressible air container," B, and

lenders resistance to the pressure applied from below. v v

The completionv and perfection of a' 'cast-.

ing by m'eansof mv pressure tools in gen:

eral is as followsz A'fterrthe metal S, is poured-by any' ordinary means, into the iiolctlfilling out approximately the space of "the-same, it is heated from the outside of the queri s illustrated in; Fig-11. In eitheiagiise provision is made.

iuold two converging flames of: a double metal to be cast is of disadvantage as it gassand oxygen blow pipe. An oxygenic flame directed upon and in'contactwith the oxidizes thefmetal readily. S g

through the mold avoids the coming incontact of the oxygenic flame with the cast metal and prevents oxidation.- The air cushion, A, is'heat'ed at the same time and the cylinder, N, is held overthe flames collecting heat inits interior n order to be telescoped at the proper moment over the walls of the cup C, insulating the mold by; v

a hot air cushion. -The proper moment of closing thepressure flask has comeas soon as the metal'inthe inlet funnel appears ig ly liquid; Pressure .is now applied and as theralve of the conical surface X does not-admit of the hot airyithot ' air pressure that surrounds -theliquid metal and the mold investment when the metal is pressed toward the interior of the mold.

Such a perfection is obtained that the thin- 5 nestcastings as base plates, clasps, etc'., can

be reproduced by'rusing the insulating flask.

Ha.ving now fully described my invention "I claim; I V

10 for dental castings and the like having an uncovered tapering surface extension on the lower end, a mold receptacle and a supporting base; said receptacle consisting of a5? metal cup havi'nglateral walls and a bottom; the lateral \ralls freely surrounding and insulating the upper part of the mold; the bottom of the cup provided with a tapering surface extension on the inside for support- -jjibg and centeringthe mold in. the lower end 20 and a tapering surface extension on the outg'sidc; said base provided with a tapering surface extension fitt-ing the outside'of the 93 :describedand tto'm extensionjzof the cup, thereforeserv 1 2. Thei'c'ombination of aldetachable mold,

I and a base; said. flask embraclnga remov to'a ource of air pressureand fitting i ha in a tap porting the moldduring pressure applicatioxnand a tapering surface-extension on'the outside .of the bottomysai'd basemayi'n g'h t ion of the flask, thereforeserving as-a rest for said pressure flask substantially as dcscribed and shown.

,. HEINRICH SCHWEIT ERQ able, cup shaped lower section; and anupper sectionfliaving the shape of a hood possessend againsttlie-upper'end of thei of the flask; said lo\irer's'ection eri'ng si'irface'extension on the inside of i'tShOtto'm. for =centering and s up i I g ng on top a central perforation leading-di 1. The combination of a detachable mold, 5

f" taperingsurface extension'which fits to the outside surface extension of-th'e lower'sec 

